Simplify the following expression: $n = \dfrac{9}{4t} \div \dfrac{2}{9t}$
Explanation: Dividing by an expression is the same as multiplying by its inverse. $n = \dfrac{9}{4t} \times \dfrac{9t}{2}$ When multiplying fractions, we multiply the numerators and the denominators. $n = \dfrac{ 9 \times 9t } { 4t \times 2}$ $n = \dfrac{81t}{8t}$ Simplify: $n = \dfrac{81}{8}$